The mission of the Children's Oncology Group (COG) Phase 1 and Pilot Consortium is to identify and develop effective new agents for children and adolescents with cancer, through rational and efficient clinical and laboratory research. This limited institution consortium, comprised of 21 premier pediatric oncology programs in the country that were selected through a peer review process, serves as a national and international model for new agent development in pediatric oncology. The Consortium successfully leverages the database infrastructure and resources of the parent Children's Oncology Group (COG) while maintaining its own administrative and operational infrastructure to ensure rapid development, implementation and reporting of specialized and complex early phase clinical trials. The Consortium has expert resources for the conduct of translational biology, pharmacokinetic, and pharmacogenetics studies, and has developed a state-of-the art infrastructure to facilitate image transfer of specialized correlative imaging studies for central review and analyses. The Consortium's primary specific aims are: 1) To perform phase 1 trials of agents that target specific tumor types based on available data from preclinical tumor model systems, known molecular targets, and/or adult clinical trial data; 2) To collaborate with COG Disease Committees to develop and conduct pilot studies of promising new treatment approaches with specific types of cancer, based on available data from tumor model systems, the molecular profile of the tumor, and pediatric phase 1 or 2 trial data; and 3) To incorporate pharmacokinetic and pharmacodynamic endpoints, including imaging and/or translational laboratory studies, as appropriate into Phase 1 and pilot studies to facilitate future development of the new treatment approaches. The development of targeted therapy for childhood cancers is a high priority as such therapeutics offer the prospect of being more efficacious and less toxic.